Towards Correct Transformation: From High-Level Models to Time- - - PowerPoint PPT Presentation

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Towards Correct Transformation: From High-Level Models to Time- Triggered Implementations

• H. GUESMI(3), B. BEN HEDIA(1), S. BLIUDZE(2), M. JAN(1) and S.

BENSALEM(3)

(1)CEA, LIST, Embedded Real Time Systems Laboratory, 91191 Gif-sur-Yvette, France (2) EPFL IC IINFCOM RiSD, Station 14, 1015 Lausanne, Switzerland (3) Verimag, Université Joseph Fourrier, 38610 Gieres, France

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Introduction

2

Real-Time (RT) Systems

Time-Triggered (TT) Event-Triggered (ET)

How to build Embedded RT systems of guaranteed quality, in a cost-effective manner??

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Introduction

Component- based design framework

2

Real-Time (RT) Systems

Time-Triggered (TT) Event-Triggered (ET)

How to build Embedded RT systems of guaranteed quality, in a cost-effective manner??

• Abstracts away implementation details
• Validates the model through different

techniques such as formal verification, simulation, and testing Targets generic execution model

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Introduction

Component- based design framework RTOS-based implementation + TT approach

Real-Time (RT) Systems

Time-Triggered (TT)

2

Event-Triggered (ET)

How to build Embedded RT systems of guaranteed quality, in a cost-effective manner??

• Abstracts away implementation details
• Validates the model through different

techniques such as formal verification, simulation, and testing Targets generic execution model No high-level programming models to tackle complexity Implement TT execution model

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Introduction

Real-Time (RT) Systems

Time-Triggered (TT)

2

Event-Triggered (ET)

How to build Embedded RT systems of guaranteed quality, in a cost-effective manner??

Component- based design framework RTOS-based implementation + TT approach

• Abstracts away implementation details
• Validates the model through different

techniques such as formal verification, simulation, and testing Targets generic execution model No high-level programming models to tackle complexity Implement TT execution model

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Background Concepts

RT-BIP Framework [1]:

Structure of a real-time BIP model: Priorities Interactions B e h v i

• r

a

Timedautomata Connectors representinginteractions Mechanism for Conflict resolution between interactions

p1 p2 p3 q

x є [2,3] x := 0 x == 1 x := 0 L1 L2

3

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Background Concepts

RT-BIP Framework [1]:

Structure of a real-time BIP model:

TCA: Computation model of TT tasks in PharOS [2][5]:

The temporal behavior of a task is specified using a directed graph Priorities Interactions B e h v i

• r

a

Timedautomata Connectors representinginteractions Mechanism for Conflict resolution between interactions

p1 p2 p3 q

x є [2,3] x := 0 x == 1 x := 0 L1 L2

2 2 1

a b c d e f

3

Synchronization node No constraint node “After” node “Before” node “advance” node

3

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1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

Approach

TT paradigm

RT-BIP Model TT platform

Executable code

TT-BIP Model

Model-to-model Transformation

1- ?

4

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1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

Approach

TT paradigm

RT-BIP Model TT platform

Executable code

TT-BIP Model

Model-to-model Transformation

1- ?

4

TT-BIP is not easily translated to an executable

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1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

2/ Step2:

Challenges:

Approach

TT paradigm

RT-BIP Model TT platform

Executable code

TT-BIP Model TCA model

Model-to-model Transformation

1-

Model-to-code Transformation

2-

4 Constraints only on the start instant of an action Can be constrained both the release and deadline instants of an action

1

L1 L2 tc: 1≤ x ≤4 tpc: x ≤5

b

Reset x

a

? 1

a

?

b

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April 2016 | 13

&

1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

2/ Step2:

Challenges:

Approach

TT paradigm

RT-BIP Model TT platform

Executable code

TT-BIP Model TCA model

Model-to-model Transformation

1-

Model-to-code Transformation

2-

4 Constraints only on the start instant of an action Can be constrained both the release and deadline instants of an action Absolute labeling of constraints Relative labeling of constraints

1 2

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&

1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

2/ Step2:

Challenges:

Approach

TT paradigm

RT-BIP Model TT platform

Executable code

TT-BIP Model TCA model

Model-to-model Transformation

1-

Model-to-code Transformation

2-

4 Constraints only on the start instant of an action Can be constrained both the release and deadline instants of an action Absolute labeling of constraints Relative labeling of constraints Interactions = data transfer + synchronization between sending and receiving actions Desynchronized interaction= sender provides new values at each synchronizationpoint+ Receivers can consult these values when their current time is equal or higher to the defined visibility dates.

1 2 3

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1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

2/ Step2:

Challenges:

Approach

TT paradigm

RT-BIP Model TT platform

Executable code

TT-BIP Model TCA model

Model-to-model Transformation

1-

Model-to-code Transformation

2-

4 Constraints only on the start instant of an action Can be constrained both the release and deadline instants of an action Absolute labeling of constraints Relative labeling of constraints Interactions = data transfer + synchronization between sending and receiving actions Desynchronized interaction= sender provides new values at each synchronizationpoint+ Receivers can consult these values when their current time is equal or higher to the defined visibility dates.

1 2 3

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1/ Step1 [3]

TT-BIP = tasks components + communication components + unidirectional interactions.

2/ Step2:

Challenges: Correctness proof:

• Expressing semantics of each model in terms
• f Labelled Transition system (LTS).
• Proving equivalence between two LTSs by

using bisimulation technique.  trace equivalence

Approach

4 RT-BIP Model TT platform

Executable code

TT-BIP Model TCA model

Model-to-model Transformation

1-

Model-to-code Transformation

2-

LTS LTS

~

Bisimulation TT paradigm

semantics semantics

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Thank you!

[1] Tesnim Abdellatif. Rigourous Implementation of Real-Time Systems. PhD thesis, UJF, 2012. [2] C Aussagues, D Chabrol, V David, D Roux, N Willey, A Tournadre, and M Graniou. PharOS, a multicore OS ready for safety-related automotive systems: results and future prospects. Proc. of The Embedded Real-Time Software and Systems (ERTS2), 2010. [3] Hela Guesmi, Belgacem Ben Hedia, Simon Bliudze, Saddek Bensalem, and Jacques Combaz. Towards time-triggered component- based system models. In ICSEA15, pages 157–169, Barcelone, Spain, November 2015. ThinkMind. [4] Robert Kaiser and Stephan Wagner. Evolution of the PikeOS

• microkernel. In Proceedings of the 1st International Workshop on

Microkernels forEmbedded Systems, pages 50–57,2007. [5] Matthieu Lemerre, Vincent David, Christophe Aussagu`es, and Guy Vidal-Naquet. An introduction to time-constrained automata. In Proc. Of the 3 rd Interaction and Concurrency Experience (ICE 2010), volume 38

• f EPTCS, pages 83–98, 2010.